Renewable-cutter reamer



April 16, 1929. H. E. BROWN v 1,708,932

RENEWABLE CUTTER BEAMER I Filed March 5, 1928 lwatenterl diprr l@ l@RENEWABLEnUTTEH,

Application 'filed March 3, 19ml. Serial llo. 558,395.

'lllhis invention relates to reamers or underreainers and the majorobject of the invention is to provide an improved construction ot a typewherein the cutters or cutting elements inay be changed or renewedwithout litting the tool to the surface ll/ly invention is characterizedby the use ot a plurality of cutters or cutter carriers, or a pluralityot sets ot cutters or cutter carriers spaced vertically orlongitudinally from each other, a longitudinal mandrel being adapted tocause expansion and contra@ tion of the cutters or cutter carriers byreason ot relative longitudinal movement ot the mandrel. To nuove thernandrel longitudinally and under control, so as to expand or contractany selected cutter carrier or set ot cutter carriers, l provide amechanisni which ll rnay conveniently term a ratchet inechanisin,actuated by contact with the lower end ot the drill pipe., the actionbeing such that each tiine the 'tool is drawn up into contact with thelower end ot the pipe the mandrel is moved longitudinally through apredetermined distance-a step in its inoveinentf-so as either tocontract or expand sorne one cutter carrier or set et cutter carriers..

'llt will he understood that ll do not claim the broad and initialinvention oit a change able cutter rearncr in which change or renewaloicutters is eilected by drawing the tool up against the end ot thedrill pipe7 that broad invention being understood lby ine to have beenpreviously inade by others. do74 however9 claim the general type otchangeable cutter reanaer which is herein described and wherein themandrel, by virtue ot step hy step vertical movement, causes expansionand contraction9 selectively7 ot several ditlerent cutters or sets otcutters.

hly invention will now best he understood by reiter-ence to thefollowing detailed description of a preferred torna, and to theaccompanying drawings, in which:

idigure l is a longitudinal central section showing my reanier with oneset oit cutters expanded;

2 is a similar view showing all the cutters cointracted;

Fig. 3 is a crosssection on line 3--3 et llig. l;

lfig. l is a crosssection on line t--ll et Fig. l;

Fig. 5 is a cross-section on line tim-5 ot llig. l; and

Fig t3 is an. enlarged longitudinal sectional detail ot the parts at thelower end oi' the mandrel.

ln the drawings il show at l a suitable tubular body with a central boreil through it. The hody is formed at its upper end in any suitablemanner tor attachment to a drill stem and the bore 1l terms the hearingguide lor certain parts and also tornis the water course which deliverscirculating 'liuid from the hollow drill stein to the vicinity ot thecuttersu ilidahly .mounted in bore ll is a slider 12 carrying at itsupper end two pivoted triggers i3 whose upper outer ends ll are sorelated to the body that by swinging on the pivots l they may eitherextend ha` yond the cylindrical periphery ot the body or may swing in soas to he substantially Within that periphery. 'llhe two positions areshown respectively in ligs. l and 2. ylhese triggers project out throughslots itl in the body wall and their upper ends play in grooves il inthe body wallu lhe upper ends ot the triggers :may he bevelled asillustratcd and there may loe bevelled corners lia at the lower ends elgroove l@ so that when the triggers are naoved upwardly :trom theposition et towards the position ot lig. l they are also itorcedoutwardly to positions projecting beyond the periphery ol the body il.'spring Q0 urges the slider l2 upwardly and thus is constantly urging thetriggers upwardly toward the position oli llig. ltheir norrnalposition., Spring is seated on a spring scat 2l mounted in the loodylill here and a mandrel actuatinr1v rod 22 is connected at its upper endto slider l2 and extends down through the loore ll as illustrated.ll/lounted on and around 'this rod il is a cutter actuating mandrel 2Badapted to move longitudinally along the rod and longitudinally in thebore ll.y p'leierahly lll@ fitting bore 11 rather snugly so 'that thebore forms a guide for the mandrel.

The body may' be provided with any suitable number of longitudinallyspaced cutters or cutter sets. For instance, I here show three spacedcutter sets, each set comprising four cutters. And in order to show thatthe cutters may be of any desired or selected character I show theuppermost cutters as having plain cutting blades S particularly adaptedto cut shale; and I show the cutters of the two lower sets as beingroller cutters R which are adapted for cutting various kinds offormation and particularly hard formation. Rollers R are carried inpivoted cutter carriers 30 and the blades S are likewise carried insimilar pivoted cutter carriers 30. Those cutter carriers and theircutting elements play in 'slots in the body wall and are shown aspivoted to the body at 31 at their upper ends. .It will be recognizedfrom the description that these cutter car' portion or head 36 of themandrel, or by one of several such enlarged portions 36. In theparticular design here shown I illustrate a mandrel having twovertically spaced enlarged parts 36 so that, if desired, more than oneset of cutters can be expanded at one time.

Thelower end of the mandrel 23 is provided with a plurality of what maybe termed ratchet shoulders 40 arranged in vertical spacing and adaptedto be engaged by pawls 41 which are pivoted to body 1 0, the pawlsprojecting upwardly and engaging under the horizontal ratchet shoulders40. From a consideration of the drawings it will be easily understoodhow these pawls hold ,the mandrel elevated in any one of a number ofspaced positions of elevation. The lower end of the mandrelctuating rod22 is also provided with a pair of pawls 45 which'engage with a similarset of simi, larly spaced ratchet 'shoulders 46 on the inside of themandrel. A--spring 47 tends to press pawls 45 outwardly and properlyengage shoulders 46.

Suppose now that the tool is in the condition shown in Fig. 2, beinglowered through the casing C. Immediately the triggers 14 pass below thecasing the triggers are forced upwardly to the position of Fig. 1 androd 22 is raised and also mandrel 23 is raised -from the position ofFig. 2 to the position of Fig 1, by the action of pawls 45 on a ratchetshoulder 46. The amount of upward movement of rod 22 and mandrel 23 isjust enough to carry the mandrel from the position of Fig. 2 to theposition of Fig. 1, carrying the upper mandrel head 36 to a positionbetween 'the cutter carrieis 30' of the intermediate set of cutters. Theintermediate set of cutters is thus ex anded and reaming operations maybe pertornied.

If, because of wearing of the cutters, or for any other reason, it isdesired to retract this intermediate set of cutters and expand anotherset, then the tool is again pulled up until the triggers 14 contact withthe casing and are again relatively forced down to the position of Fig.2. Forcing the triggers down causes rod 22 to move downwardly butmandrel 23 cannot move downwardly because it is held up in the positionof Fig. 1 by the pawls 41. Consequently rod 22 and its pawls 45 movedown and catch on the next ratchet shoulder below; so that when the toolis again lowered away from the casing the rod 22 `moves upwardly andmoves mandrel 23 up a step in its movement. This movement of the mandrelwill .carry the up er head 36 to a position above 'the intermediate setof cutters and allow those cutters to contract. The cutters are now allcontracted, just as they were when the mandrel was in the position ofFig. 2. In any such contracted position the tool may be lowered throughthe casing or pulled out through the casing. If it is desired however to-expand another set of cut-ters, then thetool is again raised so thatthe triggers come into contact with the casing and are again pusheddown; and when the tool is then lowered from the casing the triggers androd 22 again move upwardly, moving mandrel 23 up through another step ofits movement. This movement of the mandrel will carry the upper head 36to a position between the uppermost cutter carriers 30 and cause them tobe expanded; and drillingr operations may then be carried on with thosecutters.

From what I have said it will be seen that the essence of the cutterexpanding and contracting operation lies in the fact that the severalsets of cutters are spaced apart vertically and that the mandrel ismoved step by step through successive distances equal to about one-halfthe distance between adjacent sets of cutters; so that at successiveactuations first one set of cutters is expanded, then next all thecutters are contracted and then next another set of cutters is expanded.And it will now readily be'seen'how any number of cutter sels can bearranged in my tool to be selectively expanded and contracted in such amanner that any one set of cutters can be expanded and thus substitutedin operation for any other set of cutters. And the arrangement may alsobe made to expand more than one set of cutters at one time. Forinstance, as shown in the drawings, the mandrel may also have a lowerhead 36 so placed thatl when the upper head 36 is in operative positionbetween the uppermost cutter carriers the lower head 36 will be inoperative position between the lower sot of cutter carriers. rllhus, inthe particular design here shown, either the intermediate set or theuppermost set may be expanded as the operator may desire; and also thelowermost set may be expanded simultaneously with the uppermost set.

Other variations and modifications will occur to those skilled in theart. I do not here attempt to explain all modifications that may be madewithin my invention7 butl it will be understood that the invention isnot limited to the specilic structures which have been described indetail except in so far expressly so stated in the following claims.

l claim:

l. An expansive reamer of the character described, comprising a body, aplurality ot cutter carriers mounted in the body in vertically spacedrelation and each cutter carrier movable transversely of the body forexpansion and contraction, a vertically movable mandrel in the body andhaving a carrier engaging part adapted to engage one carrier when in onevertical position and another carrier when in another vertical position,and means actuatable by engagement with a well casing to move themandrel vertically between its two carrier engaging positions.

2. An expansive rcamer of the character described, comprisingJ a body, aplurality of cutter carriers mounted in the body in vertically spacedrelation and each cutter carrier movable transversely of the body Jforexpal sion and contraction, a vertically movable mandrel in the body andhaving a carrier engaging part adapted to engage one carrier when in onevertical position and another carrier when in another vertical position,and means actuatable by engagement with a well casing to move the.mandrel vertically in step by step movement.

3, An expansive reamer of the character described, comprising a body, aplurality of cutter carriers mounted in the body 'in vertically spacedrelation and each cutter carrier movable transversely of the body 'forexpansion and contraction, a vertically movable mandrel in the body andhaving a car-` rier engaging part adapted to engage one carrier when inone vertical position and another carrier when in another verticalposition, and means actuatable by engagement with a well casing to movethe mandrel vertically, said means embodying a vertically reciprocablemember, a spring urging said member upwardly, a trigger carried by saidmember and adapted to be engaged by the lower end of the casing to bemoved down relative to the body, and a ratchet mechanism acting betweenthe reciprocable inember and the mandrel.

t. An expansive reainer of the character described, comprising a body, aplurality of cutter carriers mounted in the body in vertically spacedrelation and each cutter carrier movable transversely .of the body :forexpansion and contraction, a vertically movable mandrel in the body andhaving a carrier engaging part adapted to engage one carrier when in onevertical position and another carrier when in another vertical position,andmeans actuatable by engagement with a well casing to move the mandrelverticallysaid means comprising a vertically reciprocable member in thebody having a limited vertical movement equal substantially to half thedistance between the vertically spaced cutters, a spring urging saidmember upwardly, a trigger connected with said member and ada ted to beengaged by the casing to move 1t downwardly, a ratchet mechanismsupporting the mandrel in the body, and a ratchet mechanism actingbetween said member and the mandrel to cause upward movement of themandrel with said member.

5. An expansive reamer of the character described, comprising a body, aplurality of cutter carriers mounted in the body in vertically spacedrelation and each cutter carrier lmovable transversely of the body forexpansion and contraction, a vertically movable mandrel in the body andhaving a carrier engaging part adapted to engage one carrier when in onevertical position and another carrier when in another vertical position,and means actuatable by engagement with a well casing'to move themandrel vertically, said means comprising a vertically reciprocablemember in the body having a limited vertical movement equalsubstantially to half the distance between the vertically spacedcutters, a spring urging said member upwardly, a trigger connected withsaid member and adapted to be engaged by the casing to move itdownwardly, a ratchet mechanism supporting the mandrel in the body, anda ratchet mechanism acting between said member and the mandrel to causeupward movement of the mandrel with said member, each of said ratchetmeans embodying spaced ratchet shoulders whoseV spacing is substantiallyequal to halt the distance between the vertically spaced carriers.

6. An expansive reamer of the character described, comprising a body, aplurality of critter cariiers mounted in the body in vertically spacedrelation and each cutter carrier movable transversely of the body forexpansion and contraction, a vertically movable mandrel in the body andhaving a caryrier engaging part adapted to engage one carrier when inone vertical position and another carrier when 1n another verticalposition, and means actuatable by engagement With a Well casing to movethe mandrel up- Wardly, at each such actuation, through a distancesubstantially equal to half the distance between the vertically spacedcarriers.

In Witness that I claim the foregoing I have hereunto subscribed my namethis 2nd day of February, 1928.

HARRY E. BROWN.

